<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
.wave {
    position: relative;
    font-size: 0;
}
.wave > div {
    width: 6px;
    height: 10px;
    display: inline-block;
    background-color: #0ff;
    margin-right: 6px;
    animation: wave 1.5s infinite ease-in-out;
}
.wave > div:nth-child(2) {
    animation-delay: 0.2s;
}
.wave > div:nth-child(3) {
    animation-delay: 0.4s;
}
.wave > div:nth-child(4) {
    animation-delay: 0.6s;
}
.wave > div:nth-child(5) {
    animation-delay: 0.8s;
}
@keyframes wave {
    0%, 40%, 100% {
        transform: scaleY(1);
    }
    20% {
        transform: scaleY(3);
    }
}
</style>
</head>
<body>
<div class="wave">
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
</div>
</body>
</html>